--- /dev/null
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package runtime
+
+import "unsafe"
+
+const (
+ c0 = uintptr((8-uint64(ptrSize))/4*2860486313 + (uint64(ptrSize)-4)/4*33054211828000289)
+ c1 = uintptr((8-uint64(ptrSize))/4*3267000013 + (uint64(ptrSize)-4)/4*23344194077549503)
+)
+
+const (
+ alg_MEM = iota
+ alg_MEM0
+ alg_MEM8
+ alg_MEM16
+ alg_MEM32
+ alg_MEM64
+ alg_MEM128
+ alg_NOEQ
+ alg_NOEQ0
+ alg_NOEQ8
+ alg_NOEQ16
+ alg_NOEQ32
+ alg_NOEQ64
+ alg_NOEQ128
+ alg_STRING
+ alg_INTER
+ alg_NILINTER
+ alg_SLICE
+ alg_FLOAT32
+ alg_FLOAT64
+ alg_CPLX64
+ alg_CPLX128
+ alg_max
+)
+
+var use_aeshash bool
+
+// in asm_*.s
+func aeshash(p unsafe.Pointer, s uintptr, h uintptr) uintptr
+
+func memhash(p unsafe.Pointer, s uintptr, h uintptr) uintptr {
+ if use_aeshash {
+ return aeshash(p, s, h)
+ }
+
+ h ^= c0
+ for s > 0 {
+ h = (h ^ uintptr(*(*byte)(p))) * c1
+ p = add(p, 1)
+ s--
+ }
+ return h
+}
+
+func strhash(a *string, s uintptr, h uintptr) uintptr {
+ return memhash((*stringStruct)(unsafe.Pointer(a)).str, uintptr(len(*a)), h)
+}
+
+// NOTE: Because NaN != NaN, a map can contain any
+// number of (mostly useless) entries keyed with NaNs.
+// To avoid long hash chains, we assign a random number
+// as the hash value for a NaN.
+
+func f32hash(a *float32, s uintptr, h uintptr) uintptr {
+ f := *a
+ switch {
+ case f == 0:
+ return c1 * (c0 ^ h) // +0, -0
+ case f != f:
+ return c1 * (c0 ^ h ^ uintptr(fastrand2())) // any kind of NaN
+ default:
+ return c1 * (c0 ^ h ^ uintptr(*(*uint32)(unsafe.Pointer(a))))
+ }
+}
+
+func f64hash(a *float64, s uintptr, h uintptr) uintptr {
+ f := *a
+ switch {
+ case f == 0:
+ return c1 * (c0 ^ h) // +0, -0
+ case f != f:
+ return c1 * (c0 ^ h ^ uintptr(fastrand2())) // any kind of NaN
+ case ptrSize == 4:
+ x := (*[2]uintptr)(unsafe.Pointer(a))
+ return c1 * (c0 ^ h ^ (x[1] * c1) ^ x[0])
+ default:
+ return c1 * (c0 ^ h ^ *(*uintptr)(unsafe.Pointer(a)))
+ }
+}
+
+func c64hash(a *complex64, s uintptr, h uintptr) uintptr {
+ x := (*[2]float32)(unsafe.Pointer(a))
+ return f32hash(&x[1], 4, f32hash(&x[0], 4, h))
+}
+
+func c128hash(a *complex128, s uintptr, h uintptr) uintptr {
+ x := (*[2]float64)(unsafe.Pointer(a))
+ return f64hash(&x[1], 4, f64hash(&x[0], 4, h))
+}
+
+func nohash(a unsafe.Pointer, s uintptr, h uintptr) uintptr {
+ panic(errorString("hash of unhashable type"))
+}
+
+func interhash(a *interface {
+ f()
+}, s uintptr, h uintptr) uintptr {
+ return 0
+}
+
+func nilinterhash(a *interface{}, s uintptr, h uintptr) uintptr {
+ t := (*eface)(unsafe.Pointer(a))._type
+ if t == nil {
+ return h
+ }
+ fn := goalg(t.alg).hash
+ if **(**uintptr)(unsafe.Pointer(&fn)) == nohashcode {
+ // calling nohash will panic too,
+ // but we can print a better error.
+ panic(errorString("hash of unhashable type " + *t._string))
+ }
+ if uintptr(t.size) <= ptrSize {
+ return c1 * fn(unsafe.Pointer(&(*eface)(unsafe.Pointer(a)).data), uintptr(t.size), h^c0)
+ } else {
+ return c1 * fn((*eface)(unsafe.Pointer(a)).data, uintptr(t.size), h^c0)
+ }
+}
+
+// Testing adapters for hash quality tests (see hash_test.go)
+func haveGoodHash() bool {
+ return use_aeshash
+}
+
+func stringHash(s string, seed uintptr) uintptr {
+ return goalg(&algarray[alg_STRING]).hash(noescape(unsafe.Pointer(&s)), unsafe.Sizeof(s), seed)
+}
+
+func bytesHash(b []byte, seed uintptr) uintptr {
+ // TODO: use sliceStruct
+ return goalg(&algarray[alg_MEM]).hash(*(*unsafe.Pointer)(unsafe.Pointer(&b)), uintptr(len(b)), seed)
+}
+
+func int32Hash(i uint32, seed uintptr) uintptr {
+ return goalg(&algarray[alg_MEM32]).hash(noescape(unsafe.Pointer(&i)), 4, seed)
+}
+
+func int64Hash(i uint64, seed uintptr) uintptr {
+ return goalg(&algarray[alg_MEM64]).hash(noescape(unsafe.Pointer(&i)), 8, seed)
+}